(Reuters) - Las Vegas casinos aren't against Denver Broncos quarterback Peyton Manning winning a Super Bowl in what is likely his final game but prefer the Carolina Panthers deny him a fairytale finish without covering the spread.
If top-seeded Carolina win the National Football League's title game on Sunday and cover the 5-1/2 point spread it will be much less favorable for the house than if Denver were to lose the game and stay within the spread.
MGM Resorts International, which operates 10 sports book on the Las Vegas Strip, expect most bets to come during the final 24 hours before kickoff but admitted a trend is in place.
"If it continues to pace the way it's pacing we're going to be massive Broncos fans. We're going to want the favourite-to-win-but-not-cover scenario," Jay Rood, vice president of the race and sports book at MGM Resorts, told Reuters.
"A Broncos win wouldn't be disastrous, but it wouldn't be the best-case scenario for us."
Denver, who have 39-year-old future Hall of Famer Peyton Manning at the helm of their offense, are seeking a third title in their record-equaling eighth Super Bowl appearance.
Carolina, appearing in only their second Super Bowl, will be relying heavily on the NFL's highest-scoring offense led by Cam Newton in their quest for a maiden title.
Sports bettors wagered $116 million in Nevada on last year's Super Bowl, down 2.8 percent from the record $119.4 million spent the previous year when the Seattle Seahawks routed Denver.
The American Gaming Association said it expects Americans to bet $4.2 billion on the Super Bowl, up 8 percent from last year. Nearly 97 percent of those bets, or $4.1 billion, will be wagered illegally, according to the AGA.
While billions will be wagered on the Super Bowl, only a portion of the funds will be devoted to the actual winner.
Aside from more traditional bets, gamblers can take a chance at proposition bets, like deciding which team will score first and what color liquid will be poured on the winning coach.
Among some of the more unique proposition bets are whether there will be an earthquake during the game in Santa Clara, California, and whether the total points scored by the victor will be higher or lower than U.S. presidential candidate Donald Trump's percentage points in next week's New Hampshire primary.
Reporting by Frank Pingue in Toronto; Editing by Steve Keating